" 'filename' is a disk image filename\n"
" 'fmt' is the disk image format. It is guessed automatically in most cases\n"
" 'cache' is the cache mode used to write the output disk image, the valid\n"
- " options are: 'none', 'writeback' (default), 'writethrough', 'directsync'\n"
- " and 'unsafe'\n"
+ " options are: 'none', 'writeback' (default, except for convert), 'writethrough',\n"
+ " 'directsync' and 'unsafe' (default for convert)\n"
" 'size' is the disk image size in bytes. Optional suffixes\n"
" 'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G' (gigabyte, 1024M)\n"
" and T (terabyte, 1024G) are supported. 'b' is ignored.\n"